(20 points)
josephine is taking a college course, and her professor bases the course grade on the average of 2 tests taken in the semester. she wants to know what she needs to earn on the last test to maintain her grade. rearrange the following equation for b, where a is the average of 2 test scores, a and b.
a = a + b over 2
b = 2a + a
b = 2a − a
b = 2a(a)

A = a + b over 2

First multiply both sides by 2:

2A = a+b

Now subtract a from both sides:

b = 2A - a

college

when rotating a figure 180 degrees, imagine that you are able to take the figure and turn it clockwise or counterclockwise around a center point. to rotate a figure 180 degrees, you will need to apply the rule (x, y) → (-x, -y). start by using a coordinate grid with coordinates for each vertex of the figure. the center point of the coordinate grid is located at (0, 0), which is what you will rotate the figure around. write down the original coordinates of the shape you are going to rotate. then, apply the rule. for example, coordinate (1, 2) becomes (-1, -2). another example would be, coordinate (-4, -2) becoming (4, 2). after you change each original coordinate to the rotated coordinate, you will draw your new figure.

step-by-step explanation: